

import java.util.Scanner;

public class Sqrt {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            double target = sc.nextDouble();
            double m = sc.nextDouble();
            double max = target;
            double min = 1.0D;
            while (max-min > m){
                double mid = (max + min) / 2;
                if (mid * mid > target) {
                    max = mid;
                } else if (mid * mid < target) {
                    min = mid;
                }else {
                    System.out.println(mid);
                }

            }
            System.out.println(max);
        }
    }
}
